drm/amdgpu: Fix pcie_bw on Vega20

The registers used for VG20 are different in that certain performance
counters were split off to TXCLK3/4. Vega10/12 doesn't have this, so add
a new vg20_get_pcie_usage to reflect this change.
Signed-off-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/soc15.c

@@ -785,14 +785,9 @@ static void soc15_get_pcie_usage(struct amdgpu_device *adev, uint64_t *count0,
 
 	/* Set the 2 events that we wish to watch, defined above */
 	/* Reg 40 is # received msgs */
+	/* Reg 104 is # of posted requests sent */
 	perfctr = REG_SET_FIELD(perfctr, PCIE_PERF_CNTL_TXCLK, EVENT0_SEL, 40);
-	/* Pre-VG20, Reg 104 is # of posted requests sent. On VG20 it's 108 */
-	if (adev->asic_type == CHIP_VEGA20)
-		perfctr = REG_SET_FIELD(perfctr, PCIE_PERF_CNTL_TXCLK,
-					EVENT1_SEL, 108);
-	else
-		perfctr = REG_SET_FIELD(perfctr, PCIE_PERF_CNTL_TXCLK,
-					EVENT1_SEL, 104);
+	perfctr = REG_SET_FIELD(perfctr, PCIE_PERF_CNTL_TXCLK, EVENT1_SEL, 104);
 
 	/* Write to enable desired perf counters */
 	WREG32_PCIE(smnPCIE_PERF_CNTL_TXCLK, perfctr);
@@ -822,6 +817,55 @@ static void soc15_get_pcie_usage(struct amdgpu_device *adev, uint64_t *count0,
 	*count1 = RREG32_PCIE(smnPCIE_PERF_COUNT1_TXCLK) | (cnt1_of << 32);
 }
 
+static void vega20_get_pcie_usage(struct amdgpu_device *adev, uint64_t *count0,
+				 uint64_t *count1)
+{
+	uint32_t perfctr = 0;
+	uint64_t cnt0_of, cnt1_of;
+	int tmp;
+
+	/* This reports 0 on APUs, so return to avoid writing/reading registers
+	 * that may or may not be different from their GPU counterparts
+	 */
+	if (adev->flags & AMD_IS_APU)
+		return;
+
+	/* Set the 2 events that we wish to watch, defined above */
+	/* Reg 40 is # received msgs */
+	/* Reg 108 is # of posted requests sent on VG20 */
+	perfctr = REG_SET_FIELD(perfctr, PCIE_PERF_CNTL_TXCLK3,
+				EVENT0_SEL, 40);
+	perfctr = REG_SET_FIELD(perfctr, PCIE_PERF_CNTL_TXCLK3,
+				EVENT1_SEL, 108);
+
+	/* Write to enable desired perf counters */
+	WREG32_PCIE(smnPCIE_PERF_CNTL_TXCLK3, perfctr);
+	/* Zero out and enable the perf counters
+	 * Write 0x5:
+	 * Bit 0 = Start all counters(1)
+	 * Bit 2 = Global counter reset enable(1)
+	 */
+	WREG32_PCIE(smnPCIE_PERF_COUNT_CNTL, 0x00000005);
+
+	msleep(1000);
+
+	/* Load the shadow and disable the perf counters
+	 * Write 0x2:
+	 * Bit 0 = Stop counters(0)
+	 * Bit 1 = Load the shadow counters(1)
+	 */
+	WREG32_PCIE(smnPCIE_PERF_COUNT_CNTL, 0x00000002);
+
+	/* Read register values to get any >32bit overflow */
+	tmp = RREG32_PCIE(smnPCIE_PERF_CNTL_TXCLK3);
+	cnt0_of = REG_GET_FIELD(tmp, PCIE_PERF_CNTL_TXCLK3, COUNTER0_UPPER);
+	cnt1_of = REG_GET_FIELD(tmp, PCIE_PERF_CNTL_TXCLK3, COUNTER1_UPPER);
+
+	/* Get the values and add the overflow */
+	*count0 = RREG32_PCIE(smnPCIE_PERF_COUNT0_TXCLK3) | (cnt0_of << 32);
+	*count1 = RREG32_PCIE(smnPCIE_PERF_COUNT1_TXCLK3) | (cnt1_of << 32);
+}
+
 static bool soc15_need_reset_on_init(struct amdgpu_device *adev)
 {
 	u32 sol_reg;
@@ -893,7 +937,7 @@ static const struct amdgpu_asic_funcs vega20_asic_funcs =
 	.invalidate_hdp = &soc15_invalidate_hdp,
 	.need_full_reset = &soc15_need_full_reset,
 	.init_doorbell_index = &vega20_doorbell_index_init,
-	.get_pcie_usage = &soc15_get_pcie_usage,
+	.get_pcie_usage = &vega20_get_pcie_usage,
 	.need_reset_on_init = &soc15_need_reset_on_init,
 	.get_pcie_replay_count = &soc15_get_pcie_replay_count,
 	.reset_method = &soc15_asic_reset_method